Highly available geographically distributed web servers system

Abstract

This diploma paper describes the making of a high availability (HA) system of servers, which are set up on geographically separated locations. Methods described in this paper are suitable for low-price configurations and home server hosting. Due to financial and economical reasons only one server is hosted on each location and not a local cluster of servers. Home server hosting configurations have a higher probability of power supply failures, internet connectivity failures and hardware failures. For this reason my work is focusing on disaster recovery and achieving high availability of servers. The designed HA system is transparent to the user, which means that in normal circumstances all of the connected servers appear to be working as one logical system, distributing their data across all servers. In case of failure, clients connected to the failing server are reconnected to a working server without losing their global session on the system.